[Backport release-1.0] [dashboard] Add secret-hash annotation to KeycloakClient for secret sync (#2240)

# Description
Backport of #2231 to `release-1.0`.

packages/system/dashboard/templates/keycloakclient.yaml

@@ -49,6 +49,8 @@ apiVersion: v1.edp.epam.com/v1
 kind: KeycloakClient
 metadata:
   name: dashboard-client
+  annotations:
+    secret-hash: {{ $dashboardClient | sha256sum }}
 spec:
   serviceAccount:
     enabled: true